A quick guide to fats.
Check on your own fat types incorporated into body tissue with OmegaQuant Omega-3 Index Complete Fatty Acid Profile Blood Test Kit @AMAZON.
PUFAs = Poly Unsaturated Fatty Acids
Unstable and prone to breakdown (oxidation) into toxic substances, especially when heated because of their “unsaturated” bonds (lacking two hydrogen atoms). Yet PUFAs are used by the millions of tons for cooking oil.
Primary intake of this type of fat is from seed oils aka "vegetable" oils : corn oil, soybean oil, cottonseed oil, rapeseed (canola) oil, etc. The largest component of most PUFAs is linoleic acid, needed only in very small amounts by the body, and thought to be inflammatory.
Metabolically, PUFAs incorporated into body tissue are suspect as causing weight gain, and causing degraded function all over the body by being prone to damage from free radicals, causing an overall systemic degradation of bodily tissues.
Trans fats came about via PUFAs such as cottonseed oil being chemically added to make them more saturated (add double hydrogen bonds). The amount of saturation is variable, making them soft to hard. Unlike natural saturated fat, trans fats are Frankenfats that do not generally exist otherwise.
Mono unsaturated fat
A fat with one double hydrogen bond but one unsaturated bond eg olive oil. More stable than PUFAs by being less prone to oxidation but still subject to oxidation relatively quickly.
Fats with double hydrogen bonds. Highly stable, highly resistant to oxidation and thus outstanding for cooking by virtue of not forming toxic oxidized byproducts.
Lard/tallow/butter/ghee from animals, coconout and palm oil.
Long targeted as “bad” fat with not a shred of credible scientific evidence, saturated fats are making a comeback as healthy and healthier and in reality they might turn out to be the healthiest fats you can eat. But medical dogma dies hard, especially trillions of dollars at stake.
There are now is at least one startup claiming to produce superior oils, via fermentation.